On 19 Oct 2006 at 11:23, Nolan wrote:
> The high-load theory is to get the rings pushed against the cylinder
> walls to help bed them in.
I have less authority on this subject than most of you, but I'll toss
out ideas anyway. I was told that it was important to vary the rpms
so that the cylinder walls wouldn't develop a ridge from the fact
that on each traverse of the piston the rings always turned around at
exactly the same place. Otherwise one should drive the engine as one
expected to use it, referring to the time well after the initial 15
minutes, of course. I took that message to heart when my Spitfire
engine was rebuilt, ran the car up to 75 (with OD on) on rt128
driving it home but never let it sit at any rpm for more than a few
seconds and never gave it full throttle for more than a second (if at
all). It has been rock-solid ever since. On the other hand, it
might just as well have been rock-solid anyway. Anecdotal evidence
carries very little weight.
Then I waw that jonmac wrote (with great authority):
> Taking the car on a long journey with more or less constant running
> at varying road and engine speeds gets every thing good and hot, so
> it beds in gradually.
This would seem to be at odds with the vary-the-rpms dictum. Far be
it from me to disgree.
--
Jim Muller
jimmuller@rcn.com
'80 Spitfire, '70 GT6+
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